Of mammals and meteors

A week later, my chapped lips have finally healed and I think all the dust is out of my hair. New Mexico definitely left its mark on me; I just got back from a long-overdue fieldwork trip. It was my first real fieldwork experience in New Mexico, aside from the whirlwind SVP field trip in 2018. This trip was special for another reason, too: it was my first fossil mammal-hunting trip.

As some may know, I’ve spent the last two and a half years broadening my horizons and studying fossil mammals. It will take some time before all of the research papers are out, but it’s safe to say that it has been a very enlightening and productive stretch, despite (or because of) everything that’s happened since January 2020. In short, my project contributes to a larger team effort, led by Steve Brusatte, trying to understand the rise of mammals after the extinction of the dinosaurs. [For a more in-depth account of mammal history, check out Steve’s excellent new book, The Rise and Reign of Mammals.] Most of the specimens the team has been working on are from New Mexico, from beds dating back to the Palaeocene (66–56 million years ago). It was these beds we were visiting on this trip.

I rolled into Albuquerque exhausted after about 15 hours of flying, and checked into one of the charming Route 66 motels, which would be where the team spent most of our free time while in town–one nearby had a particularly lively beer garden. The next morning, I was guided by ‘Burque veteran and labmate Sarah Shelley to the Natural History Museum, where we met curator Tom Williamson. Tom oversees a staggering collection of mammal fossils, and showed me drawer upon drawer of jaws, skulls, and skeletons from a true menagerie of species. Soon, though, our attention turned to the task at hand: finding even more fossils.

Gear packed, groceries bought, and cars rented, we left for a short four days in the San Juan Basin. We were a small crew, just six, including Sarah, Tom, Tom’s son Ryan, labmate Hans Püschel, Steve, and myself. We were greeted at our campsite by a fierce evening windstorm (hence the dust in my hair), but awoke the next morning to clear skies. We spent the first day surveying the areas around our campsite. After so long away from the field, it took a while for my eyes to readjust and start picking out fossils again. But quickly I started finding mammal teeth, and then they were everywhere I looked!

Over the four days, we found dozens of mammal teeth, and my personal haul included Periptychus, Psittacotherium, Mioclaenus, Anisonchus, Mixodectes, and Tetraclaenodon, among others. But perhaps the most interesting finds by the team weren’t mammals at all: Ryan found an articulated tail of a crocodile-like champsosaur, Hans found a complete turtle shell, and I found a gar with most of the skull–each familiar survivors of the end-Cretaceous extinction. Altogether, it was a successful trip, and personally, it was very informative to see the places that produced the fossils I’ve been working on over the last two years.

A special part of the trip was that it coincided with the Tau Herculid meteor shower. While in many places it was a dud, under the clear skies of the San Juan Basin, we saw dozens of meteors, which we climbed up the badlands to photograph. Something about huge starry skies always makes me contemplative, and it felt appropriate that us six mammals should appreciate a meteor shower. After all, the same phenomenon is the reason that the hills around us were filled with strange ancient mammals, the meek who inherited the Earth.